As the rapid development of wireless communication system, a user equipment such as a mobile phone and the like (also referred to terminal apparatus) plays a more and more important role in people's living. Functions other than the communication function in the user equipment, for example, access to a WLAN (Wireless Local Area Network) by utilizing the user equipment, have been used more and more. In addition, in order to facilitate the communication link and data exchange performed by the user equipment and another apparatus, interfaces such as infrared, Bluetooth, USE and the like have been becoming standard configurations of the user equipment. In particular, a Bluetooth earphone has been used more and more widely. The WLAN system, the Bluetooth system and the like all work in the ISM (Industrial, Scientific and Medical) frequency band. For example, the frequency band of 2400 MHz-2483.5 MHz is one of the international general ISM frequency bands, and is also one of the most common ISM frequency bands.
In case that the frequency band on which the communication between the user equipment and a corresponding base station is based is close to or a multiple of the frequency band on which the communication between the user equipment and another apparatus is based, such two communications may interfere with each other. For example, the wireless communication system LTE (Long Term Evolution) system is one of the super 3G (Beyond IMT-2000) systems. According to the LTE series standards [36.101], LTE system may work in several frequency bands. In these LTE working frequency bands, some frequency bands are immediately adjacent to the ISM frequency bands, such as the frequency band 40 for deploying a LTE TDD (Time Division Duplexing) system, 2300 MHz-2400 MHz; and the frequency band 7 for deploying a LTE FDD (Frequency Division Duplexing) system, 2500 MHz-2570 MHz for uplink and 2620 MHz-2670 MHz for downlink. In these LTE frequency bands, multiples of some frequency bands are also adjacent to the GPS (Global Positioning System) system, such as the frequency band 13 for deploying a LTE FDD system, 777 MHz-787 MHz for uplink and 746 MHz-756 MHz for downlink; and the frequency band 14 for deploying a LTE FDD system, 788 MHz-798 MHz for uplink and 758 MHz-768 MHz for downlink. If a LTE user equipment works in above frequency bands while the WLAN system or the Bluetooth system on the user equipment is at activated status, the LTE system and the ISM system (WLAN system, the Bluetooth system and the like) in the user equipment may interfere with each other due to adjacent frequency band leakage, and even result in communication failure due to an extremely high code error rate. If the GPS system on the user equipment is activated at the same time, the GPS system may be interfered with by the LTE system and can not work normally.
The conventional method for solving such issue is to employ higher performance transmitting filter in the transmitting terminal of the user equipment which communicates with the base station and/or in the transmitting terminal of the user equipment which communicates with another apparatus to reduce the adjacent frequency band leakage and/or suppress the harmonic frequency interference. The disadvantage is that such method may largely increase the cost of the user equipment.